API Reference > imodeljs-frontend > SelectionSet > SelectionTool > onModifierKeyTransition onModifierKeyTransition Method Called when Control, Shift, or Alt modifier keys are pressed or released. onModifierKeyTransition(_wentDown: boolean, modifier: BeModifierKeys, _event: KeyboardEvent): Promise<EventHandled> Parameter Type Description _wentDown boolean modifier BeModifierKeys _event KeyboardEvent Returns - Promise<EventHandled> Yes to refresh view decorations or update dynamics. Defined in core/frontend/src/tools/SelectTool.ts Line 582 Last Updated: 11 June, 2024